Bracket for attachment to pit props, stanchions, beams, and the like



April 16, 1940. w. SYLVESTER BRACKET FOR ATTACHMENT TO PIT PROIS, STANCHIONS, BEAMS, AND THE LIKE Filed April 22, 1938 llzl erzforx By his fllforngy:

apart from the Patented Apr. 16, 1940 Ei hth? UNITED STATES PATET O BRACKET Foa A'lfglgfilg'fENT T rrr races,

STANCHIONS,

AND THE LIKE Walter Sylvester, Tunstall, England Application This invention relates to brackets for attach ment to pit props, stanchions, beams and the like, hereinafter generically termed posts, and particularly to props and other supportsused in mines for the purpose of carrying sprags or struts, cables and the like. For simplicity the invention will be described as applied to brackets for pit props.

It is frequently desirable in coal minesyes pecially where coal cutting machines are employed, to provide support for the coal face and/or roof immediately adjacent thereto so as to prevent premature falls as the machine undermines the coal, which falls are not only a damage the machine or at least cause expensive delay in its operation. Supports or sprags are often required for other purposes, for example, to carry beams, cables, etc. It is not practicable to fit such supports from the ground as they would be in the way of the machine as along the coal face and the only practicable method is to attach additional and inclined supports to the first line of props so as to spring from a point well above A the floor level.

Where metal pit props are used this calls for some form of clamp or bracket but the practical conditions have to be considered. Firstly, a miner does not normally carry a spanner or wrench and naturally objects to such addition to his equipment. Secondly, it is an accepted fact that bolts and nuts are impracticable in a mine, because of their short life as they soon become bent or their threads damaged quite percentage loss under the conditions of use. Fittings secured by bolts take time to fit and moreover, depend for their safety upon proper tightening of the bolts which if too slack or too tight are a source of danger which cannot be ignored where speed is required and labour unskilled in their use.

The object of the invention is a bracket or clamp which can be quickly and easily fitted, adjusted and securely fixed in position on a pit prop without a spanner or other special tool.

According to the invention a bracket for a post comprises a body part, a cam formed on the body part adapted to engage theside of the post and complementary means co-acting with the cam form clampingmeans for fixing the bracket to the post; the body part being formed to support the end of a strut so that the thrust therefrom operates to tighten the clamp.

In the accompanying drawing: Fig. l is a side elevation of one example of bracket made in accordance with the invention.

Fig. 2 is a plan of Fig. l. Fig. 3 is a plan showing a modification of Fig. 1. Fig.4'is a side elevation of a modified form April 22, 1938, Great Britain April 24, 1937 4 Claims. (Cl. 248--22l) Serial No. 203,530

I of bracket made in accordance with the inven- Fig. 5 is a planet Fig. 3 Fig.6 shows an Fig. '1 shows a further modification of bracket. As illustrated in Figs, 1 and 2, the improved bracket is of welded steel construction and comprises a rest or socket a adapted to receive the end of a strut b, which rest or socket is attached c, c and c A curved plate (1 is welded to the ends of the cams to unite them into a body and form a single cam of the full width of the standard girder prop e to which attached. Through the axis of the cams is a formed in two parts 1 and i which are halved at their inner ends and overlap, and to the outer end of each part is secured an arm inwardly projecting Both parts of the spindle are rotatable in the cams, but one of them f is also slidable to allow the arm. to open wide enough to pass the claws over the flange of the girder prop. part 1 of the. spindle to prevent any sliding movement,'while a stop h is provided in the part to limit the sliding movement. In all positions, however, the centre cam 0 supports the divided ends of the parts i and f spindle so that rotate together. i of the secured to the'insideof the adjacent cam c and shaped so that the arm secured thereto can only be moved to the open are opposite the small part of the cam and both arms and parts of the spindle are locked from rotation when in. such open position.

As will be seen, the bracket has no detachable parts or nuts or bolts to be tightened. In use, the arms or body are easily rotated to the position shown in broken line in Fig. 1 when the sliding arm can be moved outwards to the open position shown in. broken line in Fig. 2. The bracket is then easily fitted laterally to the flange of a girder prop and when the jaws are behind the edges of such flange the sliding arm may be The socket a may useful position to receive the lower end of a strut b and in moving to such position the cam is rotated and grips the flange between itself and the claws Before being finally tightened the or lowered on the prop to strut which is to be used. The'strut is then fitted and wedged into position and the thrust of the strut on the socket of the bracket effectively tightens the cam grip of the bracket on the prop. The cam contour will be alternative construction of the "example shown in Fig. l.

g having an of the There are obviously many modifications which tilt of the platform which may be resting on come Within the nature of the invention. For that portion of the side tubes projecting beyond surface plate Z to conform with the periphery others. Such scaffolding may be used as a safe- 0f the prop and by providing a shoe plate m to 'guard against small roof falls. Obviously there place behind the prop, such plate having ends 171 Will be other uses for the brackets forming the to be engaged by the claws n on the ends of the subject of this invention. For instance, to arms 11 which replace the shorter arms 9 of the strengthen a post a bracket may be used inverted example shown in Fig. 1. This shoe plate m behind the post so as to take an auxiliary post could be chained or pivoted to the arms. Alterbehind and against the main post.

q is provided to prevent damage t th p it with a platform adapted to receive and support Wall of the post. A similar chain arrangement a strut or other member so that the thrust or and shoe could be used with girder section posts. W ght therefrom 0n the platform Op rates to A sprag 0 is secured between the cam plates 0 oll the cam against the face of the post moving and 1S suitable fol eu d or H seemon posts \SIEItIVB to the complementary means and causmP lso, to allow for wear at the spindles or for to tigh en as a clamp against t e po .33 variation of thickness of the prop flange, plates A bracket ior attachment to a post, comover the claws or end of th m body part at a point eccentric to the cam face In a further modification of the first described platform adapted to receive nd upp a Strut the locking position and so prevent opening of i A bracket f9rv attachment to a D S ,comp t e arm accidentally 01 under the sti ess of thrust mg & Cam-Shaped y palii having a p vot hole from the stru or pop at the cam axis, a two-part pivot shaft in said attached thereto, the arm t being fixed while the s ur d to e Ou r ends of each part of the to provide full surface engagement with the end Shaped bdy pa-Tt also having a platform adapted with steel posts having splayed flanges, platform opei ates to rotate the cam causing it to Where the brackets may be used to form a tighten against the post. scaffold, say in a roadway supported by steel WALTER SYLVESTER. 

